<template>
  <div class="spec-preview">
    <img :src="skuImageList[Imgindex]?.imgUrl" />
    <div class="event" @mousemove="mouseMove"></div>
    <div class="big" >
      <img :src="skuImageList[Imgindex]?.imgUrl"  ref="big"/>
    </div>
    <div class="mask" ref="maskElt"></div>
  </div>
</template>

<script>
export default {
  name: "Zoom",
  props: ["skuImageList"],
  data() {
    return {
      Imgindex: 0,
    };
  },
  mounted() {
    this.$bus.$on("getImgId", (index) => {
      this.Imgindex = index;
    });
  },
  methods: {
    mouseMove(e) {
      let mouseLeft = e.offsetX;
      let mouseTop = e.offsetY;
      let maskLeft = mouseLeft - this.$refs.maskElt.offsetWidth / 2;
      let maskTop = mouseTop - this.$refs.maskElt.offsetHeight / 2;
      let bigTop = -2*maskTop
      let bigleft = -2*maskLeft


      if (maskLeft < 0) {
        maskLeft = 0;
      } else if (
        maskLeft >
        e.target.offsetWidth - this.$refs.maskElt.offsetWidth
      ) {
        maskLeft = e.target.offsetWidth - this.$refs.maskElt.offsetWidth;
      }

      if (maskTop < 0) {
        maskTop = 0;
      } else if (
        maskTop >
        e.target.offsetHeight - this.$refs.maskElt.offsetHeight
      ) {
        maskTop = e.target.offsetHeight - this.$refs.maskElt.offsetHeight0;
      }

      this.$refs.maskElt.style.left = maskLeft + "px";
      this.$refs.maskElt.style.top = maskTop + "px";
      this.$refs.big.style.top = bigTop + "px";
      this.$refs.big.style.left = bigleft + "px";
      // console.log( e.target.offsetWidth,'index');
    },
  },
};
</script>

<style lang="less">
.spec-preview {
  position: relative;
  width: 400px;
  height: 400px;
  border: 1px solid #ccc;

  img {
    width: 100%;
    height: 100%;
  }

  .event {
    width: 100%;
    height: 100%;
    position: absolute;
    top: 0;
    left: 0;
    z-index: 998;
  }

  .mask {
    width: 50%;
    height: 50%;
    background-color: rgba(0, 255, 0, 0.3);
    position: absolute;
    left: 0;
    top: 0;
    display: none;
  }

  .big {
    width: 100%;
    height: 100%;
    position: absolute;
    top: -1px;
    left: 100%;
    border: 1px solid #aaa;
    overflow: hidden;
    z-index: 998;
    display: none;
    background: white;

    img {
      width: 200%;
      max-width: 200%;
      height: 200%;
      position: absolute;
      left: 0;
      top: 0;
    }
  }

  .event:hover ~ .mask,
  .event:hover ~ .big {
    display: block;
  }
}
</style>